PHYSICAL PROCESSING AND ANALYSYS OF MATERIALS CONTENT OF SMALL-SIZE WASTE ELECTRIC AND ELECTRONIC EQUIPMENT (WEEE): A CASE OF SMARTPHONES PRINTED CIRCUIT BOARDS

Autores

  • Tamires A. da Silveira University of Vale do Rio dos Sinos (UNISINOS)
  • Kátia E.O. Dorneles University of Vale do Rio dos Sinos (UNISINOS)
  • Feliciane A. Brehm University of Vale do Rio dos Sinos (UNISINOS)
  • Carlos A.M. Moraes University of Vale do Rio dos Sinos (UNISINOS)

Palavras-chave:

Recycling; Smartphones; Recovery.

Resumo

Due to a wide variety of components, cell phones are some of the most complex electronic devices. Indirectly, technological advancements cause negative environmental impact due to the disposal of obsolete cell phones. One of the ways to minimize such impact is the recovery of materials. This study analyzed the recovery of metals from smartphones, especially in printed circuit boards (PCBs), using physical processes. The devices collected were manually disassembled, PCBs components were removed by thermal processing and ground in a knife mill. Five fractions of different grain size ranges were then separated by sieving. The material was analyzed by X-ray fluorescence, inductively coupled plasma mass spectroscopy (ICP-MS), and thermogravimetric analysis. The main components of smartphones were polymers (28%), battery (23%), display (19%), PCB (17%), others (10%), and small metal parts (3.5%). After milling, 48% wt. of PCBS were observed in the grain size fraction between 1 and 2 mm, which included the highest amount of Cu, Fe, Al, Sn, Pb, and Ni. Mechanical processing was efficient to recover metals like copper (22.4%) and tin (1.04%), which were the most abundant metals in cell phones, as observed by ICP-MS. Over 50% of the fractions analyzed was composed of copper, making smartphones an interesting source of materials, in addition to other metals that may be recovered. Toxic metals like Cd and Pb are present in PCBs of the smartphones analyzed, underscoring the importance of appropriate treatment for this kind of waste to prevent environmental impacts.

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Publicado

07-08-2021